Brush for dynamo-electric machines.



E. R. KNIGHT. BRUSH :FCR DYNAMC ELECTRIC MACHINES.

APPLIGATION FILED PEB. 7.- 1906.

932,616, Patented Aug. 31,l 1909.

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.ATTDRNEY UNITED STATES PATENT OFFICE.

EABLE RAWLINGS KIGHT, OF NOBWOOD, OHIO, ASSIGNOB. TO THE BULLOCK-ELECTBIC MANUFACTURING COMPANY, A CORPORATION OF OHIO.

BRUSH FOR DYNAMIC-ELECTRIC MACHINES.

Specification of Letters Patent. Patented Aug. 31, 1909.

Application fled February 7, 1906. Senal No. 299,871.

To all whom it may concern:

Be it known that I, EARLE R. KNIGHT, citizen of the United States, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and usefulv Improvements in Brushes for Dynamo- Electric Machines, of which the following is a full, clear, and exact specification.

My linvention relates to brushes namo-electric machines.

Heretofore, theflexible conductors or pig tails have beenv connected tothe carbon blocks in a 'variety offwa s, none of which have proved entirely satis actory.

The main object of my inventlon is to provide a connecting means' for the flexible conduct-ors and the carbon blocks which will be good both mechanically and electrically and which will permit the parts to be 'quickly and inexpensively assembled.

A further object is to provide on the brush an improved form of brush holder guide plate.

In carrying out the first part of my invention, I provide a brush with a channel or opening extending through the body portion and connect the iexible conductor to the brush by means of a hollow rivet located in the channel. The end of the brush, provided with the channel is preferably copper plated so that there will be good electric contact between the rivet and the wall of the channel and between the conductor,

for dywhich in the preferred construction is pro-- vided with a connection clip, of the brush.

In carryingout the second part of my invention I provide on one side of the brush a brushl holder guide plate which extends over the top of the brush. The plate and dexible conductor are preferably arranged on opposite sides of the brush and are held thereto' by "the hollow rivet.

My invention further consists in certain novel details `of construction and combinations of elements described in the specification and set forth in the appended claims.

For a better understanding of my invention, reference is had to the accompanying drawing, in which- Figure 1is a vertical section through the carbon brush showing the form of connection`between the carbon blockL and the ilexible conductor; Fig. 2 is a view in elevation and the body of one side of the brush; and `Fig. 3 is a view in elevation of the opposite side of the brush.

Referring now to t-he ligures of the drawing, I have shown at l0 a brush for dynamoelectric machines,4 which brush is preferably of carbon. The lower end of this brush is beveled so that a larger bearing surface between the brush and the commutator of the dynamo-electric machine can be obtained. The upper end 'of the brush is also beveled for a purpose to be explained later. The

brush is provided near its upper end with a transverse opening or channel 11 extending through the body of the' brush from side to side. In order that there lmay' bea good electrical contact between the brush and the conductor connected thereto, the upper part pf the brushis preferably copper plated as indicated at 12. The plating-is done after the channel is provided so that the walls of the latter as well as theouter parts of the brush are well coated. l

The flexible conductor or pig tail is shown atl. This flexible conductor has at its outer end a clip 14, by means of which connection can be made between. the brush and the brush holder or brush stud, and at its opposite end with a clip 15 by means of which the conductor can be securely held to the carbon block. The clip 15 is connected to thecarbon block by means of a hollow rivet 16 located within the channel 11. As is shown the clip surrounds the end of the rivet and is held between the body of the brush andthe beaded or upset end 17- of the rivet. The rivet 16 serves not only to hold the piof tail .to the brush but also to hold the`guide plate 18 thereto. Thisguide plate is on the o posite side of the brush from the pigtail and is held in place by thebeaded or upset end 19 of the opposite end of the rivet. This guide plate has two parallel sides 20 and 21 which are adapted to fit into a groove in the brush holder so as to guide the brush in its movement toward and away from the commutator. In order that there 'may3 be no relative rotative movement between the carbon brush and the guide plate I extend the plate up over the end of the brush and for a short distance down the beveled portion as shown at 22. `It is Seen that all rotative movement between the gdie plate and the brush is prevented by this extension at the end of the brush. The washer 23 in this case is between the guide plate and the end 19 of the rivet.

As is clearly shown in Fig. 1, the clip of the conductor 13 bears against the copper plated portion of the brush. This'will insure good electrical contact between the clip and the brush. VAs also appears from `the drawing, the body of the rivet bears against the copper plated wall of the channel. This also enhances the electric contact and reduces the resistance of the connection. When the ends of the rivet are upset or beaded, the body of the rivet is forced a ainst the wall of the channel and both the clip 15 and plate 18 are tightly held between the ends of the rivet and body of thecarbon. Furthermore, when the connection is made a tool is preferably inserted within the rivet so as to expand th'e ends of the latter and spread the material outward against the brush and the metal parts held thereto, so as to provide a more perfect connection than could be obtained were a solid rivet employed. I have in this case shown the conductor connected to the brush by means of the rivet and clip. It may be desired. to dispense with the clip, in which case the end of the flexible conductor will be held directly between the brush and theend of the rivet.

I aim in my claims to cover all modifications which do not involve a departure from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent is 1. A brush for dynamo-electric machines, comprising a carbon block having a' channel extending therethrough, a brush holder guide comprising a plate having parallel sides and having a portion extending up over` the end of said brush, a flexible. conductor having a clip on the opposite side of said brush, and means for `attaching said guide plate and said clip to the brush, said means comprising a rivet in said channel.

2. A brush for dynamo-electric machines, comprising a carbon block having a channel extendin therethrough, a guide plate for -a brush ho der on one side of the brush, a conductor clip on the opposite side of said brush, and ahollow rivet in said channel for connecting the plate and the clip to said brush.4

3. A brush for dynamo-electric machines, comprising a carbon block having a channel near its up r end, a portion of said brush including 't 'walls of the channel being electroplated, a uide plate on one side of the brush, a con ueber clip on theopposite sideof 'said brush, and means for securing both plates to the brush comprising a hollow rivet having its bod portion located in said channel and `its en. s beaded over the plate and the clip. i

4. In combination, a brush, and a brush helder guide plate riveted only to one side thereof, said plate being bent over the end of the brush. i

In testimony whereof I aiix my signature, in the presence of twe witnesses.

EARLE RAWLINGS KNIGHT.

Witnesses: l

ARTHUR F. Kwis, FRED J. KINSEY. 

